Is there way to check correctness of mongoDB connection?

Question

In my spring boot application i use spring-boot-starter-data-mongodb:2.1.3 to get coonection for MongoDB. I have some properties file to config mongoDB:

 spring.data.mongodb.host=localhost
 spring.data.mongodb.port=27017
 spring.data.mongodb.database=database

If i set incorrect host name (spring.data.mongodb.host=incorrect host) or port my application starts successfully. But i want that application to fail as same as when i set host name with wrong format (spring.data.mongodb.host=hxxt://wrongFormat)

Caused by: com.mongodb.MongoException: host and port should be specified in host:port format

How can i do that?

Example:

application.propertires

 #Wrong host
 spring.data.mongodb.host=www.google.com
 spring.data.mongodb.port=27017
 spring.data.mongodb.database=database

DemoApplication.java:

 @SpringBootApplication
 public class DemoApplication {
    public static void main(String[] args) {
       SpringApplication.run(DemoApplication.class, args);
    }
 }

Config.java:

@Configuration
public class Config {
    @Bean
    public CommandLineRunner commandLineRunner(JobRepository jobRepository ){
        return args -> jobRepository.findById("1");
    }
}  

JobRepository.java:

  public interface JobRepository extends MongoRepository<Job, String> {}

Job.java:

  @Getter
  @Setter
  @EqualsAndHashCode
  @NoArgsConstructor
  @Document(collection = "Jobs")
  public class Job {
     @Id
     private String id = null;
     private String field;
  }

Answer 1

If you are using mongo version 4+. May be you can try with older version if spring API has same class available package org.springframework.data.mongodb.monitor.ConnectionMetrics. Then you can use a generic approach where you can stop your bean creation by using the following code.

Spring mongo also verifies the number of connection using the same method. This method is part of Spring mongo library not the mongo-core library.

import com.mongodb.client.MongoClient;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.mongodb.MongoDatabaseFactory;
import org.springframework.data.mongodb.core.convert.DbRefResolver;
import org.springframework.data.mongodb.core.convert.DefaultDbRefResolver;
import org.springframework.data.mongodb.core.convert.DefaultMongoTypeMapper;
import org.springframework.data.mongodb.core.convert.MappingMongoConverter;
import org.springframework.data.mongodb.core.mapping.MongoMappingContext;
import org.springframework.data.mongodb.monitor.ConnectionMetrics;

@Configuration
public class MongoConfig {

@Autowired
private MongoDatabaseFactory mongoDbFactory;
@Autowired
private MongoMappingContext mongoMappingContext;
@Autowired
private MongoClient mongoClient;

@Bean
public MappingMongoConverter mappingMongoConverter() {

    DbRefResolver dbRefResolver = new DefaultDbRefResolver(mongoDbFactory);
    MappingMongoConverter converter = new MappingMongoConverter(dbRefResolver, mongoMappingContext);
    converter.setTypeMapper(new DefaultMongoTypeMapper(null));
    //This line of code checks the connection with database is there or not.
    new ConnectionMetrics(mongoClient).getAvailable();

    return converter;
}

}

This code handles two features first to avoid _class field in the database. If you are not interest in that then you probably are interested in the last line of the code. It will throw an exception if connection is not success with the database, that will indirectly stop the creation of the bean MappingMongoConverter

Answer 2

I tried to reproduce the issue. Though it says application is started but it is getting aborted after waiting for timeout period of 30000 ms settings to connect to the cluster.

As pointed out by others, you can write some custom logic to check the connectivity or try to set decrease connectivity timeout to fail fast.

sample project code

2019-05-20 10:28:07.381  INFO 86945 --- [  restartedMain] com.demo.Application                     : Started Application in 5.882 seconds (JVM running for 6.893)
2019-05-20 10:28:07.435  INFO 86945 --- [  restartedMain] org.mongodb.driver.cluster               : Cluster description not yet available. Waiting for 30000 ms before timing out
2019-05-20 10:28:26.253  INFO 86945 --- [oogle.com:27017] org.mongodb.driver.cluster               : Exception in monitor thread while connecting to server www.google.com:27017

com.mongodb.MongoSocketOpenException: Exception opening socket
    at com.mongodb.internal.connection.SocketStream.open(SocketStream.java:67) ~[mongodb-driver-core-3.8.2.jar:na]
    at com.mongodb.internal.connection.InternalStreamConnection.open(InternalStreamConnection.java:126) ~[mongodb-driver-core-3.8.2.jar:na]
    at com.mongodb.internal.connection.DefaultServerMonitor$ServerMonitorRunnable.run(DefaultServerMonitor.java:117) ~[mongodb-driver-core-3.8.2.jar:na]
    at java.lang.Thread.run(Thread.java:745) [na:1.8.0_101]
Caused by: java.net.SocketTimeoutException: connect timed out
    at java.net.PlainSocketImpl.socketConnect(Native Method) ~[na:1.8.0_101]
    at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350) ~[na:1.8.0_101]
    at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206) ~[na:1.8.0_101]
    at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188) ~[na:1.8.0_101]
    at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392) ~[na:1.8.0_101]
    at java.net.Socket.connect(Socket.java:589) ~[na:1.8.0_101]
    at com.mongodb.internal.connection.SocketStreamHelper.initialize(SocketStreamHelper.java:64) ~[mongodb-driver-core-3.8.2.jar:na]
    at com.mongodb.internal.connection.SocketStream.open(SocketStream.java:62) ~[mongodb-driver-core-3.8.2.jar:na]
    ... 3 common frames omitted

2019-05-20 10:28:37.444  INFO 86945 --- [  restartedMain] ConditionEvaluationReportLoggingListener : 

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2019-05-20 10:28:37.452 ERROR 86945 --- [  restartedMain] o.s.boot.SpringApplication               : Application run failed

java.lang.IllegalStateException: Failed to execute CommandLineRunner
    at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:816) [spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
    at org.springframework.boot.SpringApplication.callRunners(SpringApplication.java:797) [spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:324) [spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1260) [spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1248) [spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
    at com.demo.Application.main(Application.java:12) [classes/:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_101]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_101]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_101]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_101]
    at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) [spring-boot-devtools-2.1.3.RELEASE.jar:2.1.3.RELEASE]
Caused by: org.springframework.dao.DataAccessResourceFailureException: Timed out after 30000 ms while waiting to connect. Client view of cluster state is {type=UNKNOWN, servers=[{address=www.google.com:27017, type=UNKNOWN, state=CONNECTING, exception={com.mongodb.MongoSocketOpenException: Exception opening socket}, caused by {java.net.SocketTimeoutException: connect timed out}}]; nested exception is com.mongodb.MongoTimeoutException: Timed out after 30000 ms while waiting to connect. Client view of cluster state is {type=UNKNOWN, servers=[{address=www.google.com:27017, type=UNKNOWN, state=CONNECTING, exception={com.mongodb.MongoSocketOpenException: Exception opening socket}, caused by {java.net.SocketTimeoutException: connect timed out}}]
    at org.springframework.data.mongodb.core.MongoExceptionTranslator.translateExceptionIfPossible(MongoExceptionTranslator.java:90) ~[spring-data-mongodb-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.data.mongodb.core.MongoTemplate.potentiallyConvertRuntimeException(MongoTemplate.java:2774) ~[spring-data-mongodb-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.data.mongodb.core.MongoTemplate.executeFindOneInternal(MongoTemplate.java:2629) ~[spring-data-mongodb-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.data.mongodb.core.MongoTemplate.doFindOne(MongoTemplate.java:2353) ~[spring-data-mongodb-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.data.mongodb.core.MongoTemplate.findById(MongoTemplate.java:843) ~[spring-data-mongodb-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.data.mongodb.repository.support.SimpleMongoRepository.findById(SimpleMongoRepository.java:118) ~[spring-data-mongodb-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_101]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_101]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_101]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_101]
    at org.springframework.data.repository.core.support.RepositoryComposition$RepositoryFragments.invoke(RepositoryComposition.java:359) ~[spring-data-commons-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.data.repository.core.support.RepositoryComposition.invoke(RepositoryComposition.java:200) ~[spring-data-commons-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$ImplementationMethodExecutionInterceptor.invoke(RepositoryFactorySupport.java:644) ~[spring-data-commons-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:608) ~[spring-data-commons-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.lambda$invoke$3(RepositoryFactorySupport.java:595) ~[spring-data-commons-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:595) ~[spring-data-commons-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:59) ~[spring-data-commons-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:93) ~[spring-aop-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.data.repository.core.support.SurroundingTransactionDetectorMethodInterceptor.invoke(SurroundingTransactionDetectorMethodInterceptor.java:61) ~[spring-data-commons-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212) ~[spring-aop-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at com.sun.proxy.$Proxy61.findById(Unknown Source) ~[na:na]
    at com.demo.TestConfig.lambda$commandLineRunner$0(TestConfig.java:15) ~[classes/:na]
    at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:813) [spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
    ... 10 common frames omitted
Caused by: com.mongodb.MongoTimeoutException: Timed out after 30000 ms while waiting to connect. Client view of cluster state is {type=UNKNOWN, servers=[{address=www.google.com:27017, type=UNKNOWN, state=CONNECTING, exception={com.mongodb.MongoSocketOpenException: Exception opening socket}, caused by {java.net.SocketTimeoutException: connect timed out}}]
    at com.mongodb.internal.connection.BaseCluster.getDescription(BaseCluster.java:179) ~[mongodb-driver-core-3.8.2.jar:na]
    at com.mongodb.internal.connection.MultiServerCluster.getDescription(MultiServerCluster.java:54) ~[mongodb-driver-core-3.8.2.jar:na]
    at com.mongodb.client.internal.MongoClientDelegate.getConnectedClusterDescription(MongoClientDelegate.java:136) ~[mongodb-driver-3.8.2.jar:na]
    at com.mongodb.client.internal.MongoClientDelegate.createClientSession(MongoClientDelegate.java:94) ~[mongodb-driver-3.8.2.jar:na]
    at com.mongodb.client.internal.MongoClientDelegate$DelegateOperationExecutor.getClientSession(MongoClientDelegate.java:249) ~[mongodb-driver-3.8.2.jar:na]
    at com.mongodb.client.internal.MongoClientDelegate$DelegateOperationExecutor.execute(MongoClientDelegate.java:172) ~[mongodb-driver-3.8.2.jar:na]
    at com.mongodb.client.internal.FindIterableImpl.first(FindIterableImpl.java:198) ~[mongodb-driver-3.8.2.jar:na]
    at org.springframework.data.mongodb.core.MongoTemplate$FindOneCallback.doInCollection(MongoTemplate.java:2813) ~[spring-data-mongodb-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.data.mongodb.core.MongoTemplate$FindOneCallback.doInCollection(MongoTemplate.java:2788) ~[spring-data-mongodb-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.data.mongodb.core.MongoTemplate.executeFindOneInternal(MongoTemplate.java:2626) ~[spring-data-mongodb-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    ... 35 common frames omitted

2019-05-20 10:28:37.457  INFO 86945 --- [  restartedMain] o.s.s.concurrent.ThreadPoolTaskExecutor  : Shutting down ExecutorService 'applicationTaskExecutor'

Process finished with exit code 0

Answer 3

Your issue is that the connection check on mongo happens asynchronously. So if the input is correct, the beans are all created by spring boot and the connection fails at a later point. You can force it to explode by defining a bean that checks the connection at startup. For example, I use this:

/**
 * This is a testing bean. It is only here to explode when the database is not available.
 * This is to counter act default spring boot behaviour where the Mongo configuration
 * will connect to a localhost DB regardless of whether it exists or not.  
 *
 */
public class MongoDatabaseVerifier {
    private static final Logger log = LoggerFactory.getLogger(MongoDatabaseVerifier.class);

    public MongoDatabaseVerifier(MongoClient mongoClient) {
        checkConnectionOrThrow(mongoClient);
    }

    /**
     * Calls {@link MongoClient#getAddress()} and throws the result away if successful 
     * @param client
     */
    void checkConnectionOrThrow(MongoClient client) { 
        client.getAddress(); // this will either succeed super fast or explode
        log.info("Database fully started ...");
    }
}

Since this bean does its check on creation, spring will only continue the startup if it succeeds. Otherwise a bean creation exception will be thrown and the startup aborted.

I hope that helps